Squeeze the juice an orange and lime into a bowl. Mash or grate the garlic using a mortar and pestle or a grater, and add it to the bowl with the sofrito, oregano, salt, adobo, and black pepper.
Slice the chicken breasts in half so they’re about ½ inch thick. This helps them cook quicker and stay juicy. Mix it all together and pour it over your chicken breasts, make sure they're fully coated, then let it marinate in the fridge for at least 5 minutes.
Heat up a grill pan or regular grill over medium-high heat and grill the chicken for a few minutes on each side until it’s fully cooked and nicely charred. Set it aside to rest.
Take the leftover marinade and pour it into a small saucepan with brown sugar and red chili flakes. Bring it to a boil, then lower the heat, and let it simmer for a few minutes until it reduces in half and thickens.
Slice the chicken, pour the mojo reduction on top, and serve it in a mojo chicken bowl. ¡Buen provecho!